74Dusted Posted July 12, 2011 Share Posted July 12, 2011 I'm looking for a wiring diagram for a '78 DT125 (Manufactured 5-77) I found one on google, but the wiring doesn't match my bike. I'm just finishing up a 12-Volt Conversion on my DT125 (easier to find parts, can use the battery in my ATVs when i'm not running the bike) and the Voltage Regulator has me confused. On the Diagram i found it shows 1 Wire (color not listed) from the Magneto going into the Regulator and a Red Wire going out to the Positive on the Battery. My bike has a Yellow wire going into the Regulator and a Black Wire connecting the Regulator to the Negative going to the Battery (connected at a Junction joining 2 ground wires together before they connect to the battery). 100% sure the wiring on my bike was untouched/original. I'd like to confirm the wiring i've got with a diagram before i connect the new regulator and finish up the 12-Volt conversion. Link to comment Share on other sites More sharing options...
Moderator Cynic Posted July 12, 2011 Moderator Share Posted July 12, 2011 I'm looking for a wiring diagram for a '78 DT125 (Manufactured 5-77) I found one on google, but the wiring doesn't match my bike. I'm just finishing up a 12-Volt Conversion on my DT125 (easier to find parts, can use the battery in my ATVs when i'm not running the bike) and the Voltage Regulator has me confused. On the Diagram i found it shows 1 Wire (color not listed) from the Magneto going into the Regulator and a Red Wire going out to the Positive on the Battery. That will be the rectifier, the regulator works with the ac, not the battery. My bike has a Yellow wire going into the Regulator and a Black Wire connecting the Regulator to the Negative going to the Battery (connected at a Junction joining 2 ground wires together before they connect to the battery). 100% sure the wiring on my bike was untouched/original. I'd like to confirm the wiring i've got with a diagram before i connect the new regulator and finish up the 12-Volt conversion. There are 2 types, one like yours connected into the yellow with a black wire connecting to earth, there is also a single wire vertion as fitted to my bike. The regulator is mounted directly to the frame unlike the earlier fender/ mudguard mounted type and that supplies the earth path. DT diagram PS introduce yourself double quick or the waterfall sandwiches will get you........ (if you don't do an intro you WILL understand) Link to comment Share on other sites More sharing options...
74Dusted Posted July 12, 2011 Author Share Posted July 12, 2011 The regulator (1 yellow wire, 1 black wire) is stamped "6V Regulator" and I think i found the Rectifier. The Rectifier looks like it is mounted underneath the fuel tank behind the Turn Signal Flasher & Ignition Coil(way up in there, had to use a drop-light to find it), it has 3 wires going to 2 connections. One of them is a yellow wire, not sure about the other two, i'm still cleaning grease & oil off the rest of the wires. I completely forgot about the Rectifier, I'm pretty sure i've got the wiring figured out now. Thanks for the reply, it reminded me to find the rectifier too Link to comment Share on other sites More sharing options...
Moderator Cynic Posted July 12, 2011 Moderator Share Posted July 12, 2011 The regulator (1 yellow wire, 1 black wire) is stamped "6V Regulator" and I think i found the Rectifier. The Rectifier looks like it is mounted underneath the fuel tank behind the Turn Signal Flasher & Ignition Coil(way up in there, had to use a drop-light to find it), it has 3 wires going to 2 connections. One of them is a yellow wire, not sure about the other two, i'm still cleaning grease & oil off the rest of the wires. I completely forgot about the Rectifier, I'm pretty sure i've got the wiring figured out now. Thanks for the reply, it reminded me to find the rectifier too Yep thats the puppy up under the tank. Be carefull though that yellow wire isn't the one that goes to the regulator, its from the mag and runs to the ig/lighting switch. There is a return from the ig/lighting sw that runs to the regulator. Link to comment Share on other sites More sharing options...
74Dusted Posted July 12, 2011 Author Share Posted July 12, 2011 Yep thats the puppy up under the tank. Be carefull though that yellow wire isn't the one that goes to the regulator, its from the mag and runs to the ig/lighting switch. There is a return from the ig/lighting sw that runs to the regulator. Thanks for the tip, i'll fix that before i finish the wiring. I'm guessing the previous owner just plugged it into the wrong connector. Fortunately i had it unplugged when i was running the bike (test runs/getting it running ok) and didn't have a battery in the bike. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted July 12, 2011 Moderator Share Posted July 12, 2011 Thanks for the tip, i'll fix that before i finish the wiring. I'm guessing the previous owner just plugged it into the wrong connector. Fortunately i had it unplugged when i was running the bike (test runs/getting it running ok) and didn't have a battery in the bike. The rectifier has a male and female connector so it couldnt easily be wired wrong. Link to comment Share on other sites More sharing options...
74Dusted Posted July 12, 2011 Author Share Posted July 12, 2011 The rectifier has a male and female connector so it couldnt easily be wired wrong. Mine has 2 male connectors (on the rectifier, the wiring is 2 female connectors). Possibly a difference between the UK & US models? It's a Stanley DE41 Rectifier. I'm installing a SH522b-12 Regulator/Rectifier from a 1986 Honda 125 ATV (one of my ATVs) It wasn't needed anymore since i installed a CB350 Honda Motorcycle engine on the ATV (and used the wiring harness and regulator from the cycle on the atv). There are some differences compared to the howto i found on here, the one in the how-to was using a Honda C90 Regulator which only has 4 Wires instead of 5. EDIT : Just to clear things up, i didn't install a CB350 engine on my DT125. I'm using parts left over from when i installed the CB350 engine on my ATV to finish the 12 Volt Conversion on my yamaha. Lol, just had to mention it, cause i confused myself when i read my own reply. Link to comment Share on other sites More sharing options...
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